Abstract: This paper presents a new method to design nonlinear
feedback linearization controller for PEMFCs (Polymer Electrolyte
Membrane Fuel Cells). A nonlinear controller is designed based on
nonlinear model to prolong the stack life of PEMFCs. Since it is
known that large deviations between hydrogen and oxygen partial
pressures can cause severe membrane damage in the fuel cell,
feedback linearization is applied to the PEMFC system so that the
deviation can be kept as small as possible during disturbances or load
variations. To obtain an accurate feedback linearization controller,
tuning the linear parameters are always important. So in proposed
study NSGA (Non-Dominated Sorting Genetic Algorithm)-II method
was used to tune the designed controller in aim to decrease the
controller tracking error. The simulation result showed that the
proposed method tuned the controller efficiently.
Abstract: The discarded clam shell waste, fossil and edible oil
as biolubricant feedstocks create environmental impacts and food
chain dilemma, thus this work aims to circumvent these issues by
using activated saltwater clam shell waste (SCSW) as solid catalyst
for conversion of Jatropha curcas oil as non-edible sources to ester
biolubricant. The characterization of solid catalyst was done by
Differential Thermal Analysis-Thermo Gravimetric Analysis (DTATGA),
X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD),
Brunauer-Emmett-Teller (BET), Field Emission Scanning Electron
Microscopy (FESEM) and Fourier Transformed Infrared
Spectroscopy (FTIR) analysis. The calcined catalyst was used in the
transesterification of Jatropha oil to methyl ester as the first step, and
the second stage was involved the reaction of Jatropha methyl ester
(JME) with trimethylolpropane (TMP) based on the various process
parameters. The formated biolubricant was analyzed using the
capillary column (DB-5HT) equipped Gas Chromatography (GC).
The conversion results of Jatropha oil to ester biolubricant can be
found nearly 96.66%, and the maximum distribution composition
mainly contains 72.3% of triester (TE).
Abstract: A circularly polarized fractal boundary microstrip
antenna is presented. The sides of a square patch along x- axis, yaxis
are replaced with Minkowski and Koch curves correspondingly.
By using the fractal curves as edges, asymmetry in the structure is
created to excite two orthogonal modes for circular polarization (CP)
operation. The indentation factors of the fractal curves are optimized
for pure CP. The simulated results of the novel polyfractal antenna
are demonstrated.
Abstract: The study deals with the challenges in developing a
test rig to test the performance of water lubricated journal bearing.
The test rig is designed to simulate the working conditions of the
bearing in order to understand their performance before they are put
in operation. The bearing that is studied is the commercially available
water lubricated bearing which has a rubber liner bonded with a rigid
metal shell. The lubricant enters the bearing axially through a
pressurized inlet tank and exits to an outlet tank which is at
sufficiently low pressure. The load on the bearing is applied through
the dead weight system which acts both in upward and downward
direction so that net load acts on the bearing. The issues in feeding
the lubricant into the bearing from the inlet side and preventing the
leakage of the lubricant is discussed. The application of the load on
the test bearing while maintaining the bearing afloat is also discussed.
Abstract: This paper aims at finding a suitable neural network
for monitoring congestion level in electrical power systems. In this
paper, the input data has been framed properly to meet the target
objective through supervised learning mechanism by defining normal
and abnormal operating conditions for the system under study. The
congestion level, expressed as line congestion index (LCI), is
evaluated for each operating condition and is presented to the NN
along with the bus voltages to represent the input and target data.
Once, the training goes successful, the NN learns how to deal with a
set of newly presented data through validation and testing
mechanism. The crux of the results presented in this paper rests on
performance comparison of a multi-layered feed forward neural
network with eleven types of back propagation techniques so as to
evolve the best training criteria. The proposed methodology has been
tested on the standard IEEE-14 bus test system with the support of
MATLAB based NN toolbox. The results presented in this paper
signify that the Levenberg-Marquardt backpropagation algorithm
gives best training performance of all the eleven cases considered in
this paper, thus validating the proposed methodology.
Abstract: Anultra-low power capacitor less low-dropout voltage
regulator with improved transient response using gain enhanced feed
forward path compensation is presented in this paper. It is based on a
cascade of a voltage amplifier and a transconductor stage in the feed
forward path with regular error amplifier to form a composite gainenhanced
feed forward stage. It broadens the gain bandwidth and thus
improves the transient response without substantial increase in power
consumption. The proposed LDO, designed for a maximum output
current of 100 mA in UMC 180 nm, requires a quiescent current of
69 )A. An undershot of 153.79mV for a load current changes from
0mA to 100mA and an overshoot of 196.24mV for current change of
100mA to 0mA. The settling time is approximately 1.1 )s for the
output voltage undershooting case. The load regulation is of 2.77
)V/mA at load current of 100mA. Reference voltage is generated by
using an accurate band gap reference circuit of 0.8V.The costly
features of SOC such as total chip area and power consumption is
drastically reduced by the use of only a total compensation
capacitance of 6pF while consuming power consumption of 0.096
mW.
Abstract: Biological conversion of biomass to methane has
received increasing attention in recent years. Grasses have been
explored for their potential anaerobic digestion to methane. In this
review, extensive literature data have been tabulated and classified.
The influences of several parameters on the potential of these
feedstocks to produce methane are presented. Lignocellulosic
biomass represents a mostly unused source for biogas and ethanol
production. Many factors, including lignin content, crystallinity of
cellulose, and particle size, limit the digestibility of the hemicellulose
and cellulose present in the lignocellulosic biomass. Pretreatments
have used to improve the digestibility of the lignocellulosic biomass.
Each pretreatment has its own effects on cellulose, hemicellulose and
lignin, the three main components of lignocellulosic biomass. Solidstate
anaerobic digestion (SS-AD) generally occurs at solid
concentrations higher than 15%. In contrast, liquid anaerobic
digestion (AD) handles feedstocks with solid concentrations between
0.5% and 15%. Animal manure, sewage sludge, and food waste are
generally treated by liquid AD, while organic fractions of municipal
solid waste (OFMSW) and lignocellulosic biomass such as crop
residues and energy crops can be processed through SS-AD. An
increase in operating temperature can improve both the biogas yield
and the production efficiency, other practices such as using AD
digestate or leachate as an inoculant or decreasing the solid content
may increase biogas yield but have negative impact on production
efficiency. Focus is placed on substrate pretreatment in anaerobic
digestion (AD) as a means of increasing biogas yields using today’s
diversified substrate sources.
Abstract: Enzyme activity was evaluated in the intestine of
juvenile dourado (Salminus brasiliensis) fed with diets containing 0,
10 or 20% of lyophilized bovine colostrum (LBC) inclusion for either
30 or 60 days. The intestinal enzymes acid and alkaline phosphatase
(ACP and ALP, respectively), non-specific esterase (NSE), lipase
(LIP), dipeptidyl aminopeptidase IV (DAP IV) and leucine
aminopeptidase (LAP) were studied using histochemistry in four
intestinal segments (S1, S2, S3 and posterior intestine). Weak
proteolitic activity was observed in all intestinal segments for DAP
IV and LAP. The activity of NSE and LIP was also weak in all
intestines, except for the moderate activity of NSE in the S2 of 20%
LBC group after 30 days and in the S1 of 0% LBC group after 60
days. The ACP was detected only in the S2 and S3 of the 10% LBC
group after 30 days. Moderate and strong staining was observed in
the first three intestinal segments for ALP and weak activity in the
posterior intestine. The activity of DAP IV, LAP and ALP were also
present in the cytoplasm of the enterocytes. In the present results,
bovine colostrum feeding did not cause alterations in activity of
intestinal enzymes.
Abstract: Control of a semi-batch polymerization reactor using
an adaptive radial basis function (RBF) neural network method is
investigated in this paper. A neural network inverse model is used to
estimate the valve position of the reactor; this method can identify the
controlled system with the RBF neural network identifier. The
weights of the adaptive PID controller are timely adjusted based on
the identification of the plant and self-learning capability of RBFNN.
A PID controller is used in the feedback control to regulate the actual
temperature by compensating the neural network inverse model
output. Simulation results show that the proposed control has strong
adaptability, robustness and satisfactory control performance and the
nonlinear system is achieved.
Abstract: Flow forming is widely used in many industries, especially in defence technology industries. Pressure vessels requirements are high precision, light weight, seamless and optimum strength. For large pressure vessels, flow forming by 3 rollers machine were used. In case of long range rocket motor case flow forming and welding of pressure vessels have been used for manufacturing. Due to complication of welding process, researchers had developed 4 meters length pressure vessels without weldment by 4 rollers flow forming machine. Design and preparation of preform work pieces are performed. The optimization of flow forming parameter such as feed rate, spindle speed and depth of cut will be discussed. The experimental result shown relation of flow forming parameters to quality of flow formed tube and prototype pressure vessels have been made.
Abstract: This paper presents the findings of an experimental investigation of important machining parameters for the horizontal boring tool modified to mouth with a horizontal lathe machine to bore an overlength workpiece. In order to verify a usability of a modified tool, design of experiment based on Taguchi method is performed. The parameters investigated are spindle speed, feed rate, depth of cut and length of workpiece. Taguchi L9 orthogonal array is selected for four factors three level parameters in order to minimize surface roughness (Ra and Rz) of S45C steel tubes. Signal to noise ratio analysis and analysis of variance (ANOVA) is performed to study an effect of said parameters and to optimize the machine setting for best surface finish. The controlled factors with most effect are depth of cut, spindle speed, length of workpiece, and feed rate in order. The confirmation test is performed to test the optimal setting obtained from Taguchi method and the result is satisfactory.
Abstract: The study investigated the implementation of the
Neural Network (NN) techniques for prediction of the loading of Cu
ions onto clinoptilolite. The experimental design using analysis of
variance (ANOVA) was chosen for testing the adequacy of the
Neural Network and for optimizing of the effective input parameters
(pH, temperature and initial concentration). Feed forward, multi-layer
perceptron (MLP) NN successfully tracked the non-linear behavior of
the adsorption process versus the input parameters with mean squared
error (MSE), correlation coefficient (R) and minimum squared error
(MSRE) of 0.102, 0.998 and 0.004 respectively. The results showed
that NN modeling techniques could effectively predict and simulate
the highly complex system and non-linear process such as ionexchange.
Abstract: We present a dedicated video-based monitoring
system for quantification of patient’s attention to visual feedback
during robot assisted gait rehabilitation. Two different approaches for
eye gaze and head pose tracking are tested and compared. Several
metrics for assessment of patient’s attention are also presented.
Experimental results with healthy volunteers demonstrate that
unobtrusive video-based gaze tracking during the robot-assisted gait
rehabilitation is possible and is sufficiently robust for quantification
of patient’s attention and assessment of compliance with the
rehabilitation therapy.
Abstract: Children today use computer based application in
various activities especially for learning and education. Many of
these tools and application such as the Computer Aided
Pronunciation Training (CAPT) systems enable children to explore
and experience them with little supervision from the adults. In order
for these tools and application to have maximum effect on the
children’s learning and education, it must be attractive to the children
to use them. This could be achieved with the proper user interface
(UI) design. As children grow, so do their ability, taste and
preferences. They interact differently with these applications as they
grow older. This study reviews several articles on how age factors
influence the UI design. The review focuses on age related abilities
such as cognitive, literacy, concentration and feedback requirement.
We have also evaluated few of existing CAPT systems and determine
the influence of age-based factors on the interface design.
Abstract: In this paper, fractional order feedback control of a ball
beam model is investigated. The ball beam model is a particular
example of the double Integrator system having strongly nonlinear
characteristics and unstable dynamics which make the control of
such system a challenging task. Most of the work in fractional order
control systems are in theoretical nature and controller design and its
implementation in practice is very small. In this work, a successful
attempt has been made to design a fractional order PIλDμcontroller
for a benchmark laboratory ball and beam model. Better performance
can be achieved using a fractional order PID controller and it is
demonstrated through simulations results with a comparison to the
classic PID controller.
Abstract: In this paper, the design of a coaxial feed single layer rectangular microstrip patch antenna for three different wireless communication band applications is presented. The proposed antenna is designed by using substrate Roger RT/duroid 5880 having permittivity of about 2.2 and tangent loss of 0.0009. The characteristics of the substrate are designed and to evaluate the performance of modeled antenna using HFSS v.11 EM simulator, from Ansoft. The proposed antenna has small in size and operates at 2.25GHz, 3.76GHz and 5.23GHz suitable for mobile satellite service (MSS) network, WiMAX and WLAN applications. The dimension of the patch and slots are optimized to obtain these desired functional frequency ranges. The simulation results with frequency response, radiation pattern and return loss, VSWR, Input Impedance are presented with appropriate table and graph.
Abstract: Generally, distributed generation units refer to small-scale electric power generators that produce electricity at a site close to the customer or an electric distribution system (in parallel mode). From the customers’ point of view, a potentially lower cost, higher service reliability, high power quality, increased energy efficiency, and energy independence can be the key points of a proper DG unit. Moreover, the use of renewable types of distributed generations such as wind, photovoltaic, geothermal or hydroelectric power can also provide significant environmental benefits. Therefore, it is of crucial importance to study their impacts on the distribution networks. A marked increase in Distributed Generation (DG), associated with medium voltage distribution networks, may be expected. Nowadays, distribution networks are planned for unidirectional power flows that are peculiar to passive systems, and voltage control is carried out exclusively by varying the tap position of the HV/MV transformer. This paper will compare different DG control methods and possible network reconfiguration aimed at assessing their effect on voltage profiles.
Abstract: Banana pseudo-stem and fruit-bunch-stem are
agricultural residues that can be used for conversion to bio-char, biooil,
and gases by using thermochemical process. The aim of this work
is to characterize banana pseudo-stem and banana fruit-bunch-stem
through proximate analysis, elemental analysis, chemical analysis,
thermo-gravimetric analysis, and heating calorific value. The ash
contents of the banana pseudo-stem and banana fruit-bunch-stem are
11.0 mf wt.% and 20.6 mf wt.%; while the carbon content of banana
pseudo-stem and fruit-bunch-stem are 37.9 mf wt.% and 35.58 mf
wt.% respectively. The molecular formulas for banana stem and
banana fruit-bunch-stem are C24H33NO26 and C19H29NO33
respectively. The measured higher heating values of banana pseudostem
and banana fruit-bunch-stem are 15.5MJ/kg and 12.7 MJ/kg
respectively. By chemical analysis, the lignin, cellulose, and
hemicellulose contents in the samples will also be presented. The
feasibility of the banana wastes to be a feedstock for thermochemical
process in comparison with other biomass will be discussed in this
paper.
Abstract: In this paper a nonlinear feedback control called augmented automatic choosing control (AACC) for a class of
nonlinear systems with constrained input is presented. When designed
the control, a constant term which arises from linearization of a
given nonlinear system is treated as a coefficient of a stable zero
dynamics. Parameters of the control are suboptimally selected by
maximizing the stable region in the sense of Lyapunov with the aid
of a genetic algorithm. This approach is applied to a field excitation
control problem of power system to demonstrate the splendidness
of the AACC. Simulation results show that the new controller can
improve performance remarkably well.
Abstract: This paper presents the effect of electric field
distribution which is an electric field intensity analysis. Consideration
of the dielectric heating of grains and insects, the rice and rice
weevils are utilized for dielectric heating analysis. Furthermore, this
analysis compares the effect of electric field distribution in rice and
rice weevil. In this simulation, two copper plates are used to generate
the electric field for dielectric heating system and put the rice
materials between the copper plates. The simulation is classified in
two cases, which are case I one rice weevil is placed in the rice and
case II two rice weevils are placed at different position in the rice.
Moreover, the probes are located in various different positions on
plate. The power feeding on this plate is optimized by using CST EM
studio program of 1000 watt electrical power at 39 MHz resonance
frequency. The results of two cases are indicated that the most
electric field distribution and intensity are occurred on the rice and
rice weevils at the near point of the probes. Moreover, the heat is
directed to the rice weevils more than the rice. When the temperature
of rice and rice weevils are calculated and compared, the rice weevils
has the temperature more than rice is about 41.62 Celsius degrees.
These results can be applied for the dielectric heating applications to
eliminate insect.